Multiple cannula systems and methods

ABSTRACT

The preferred embodiments provide, e.g., a high quality flexible tracheostomy tube assembly including an outer tracheostomy cannula and a disposable, flexible inner cannula. In preferred embodiments, the product provides a single patient use, sterile device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/429.968, flied May 6, 2003 now U.S. Pat. No. 7,681,576. The contentsof which are hereby incorporated in their entirety by reference.

BACKGROUND

1. Field of the Invention

The present invention pertains generally to multiple cannula systems andmethods and some preferred embodiments pertain to dual cannulatracheostomy tube systems and methods.

2. Description of the Related Art

Cannula assemblies are often used in medical processes. For example, inperforming a typical tracheotomy, a surgeon often surgically creates anopening in a patient's neck and into the patient's trachea (i.e.,windpipe). In this illustrative context, a cannula is often placedthrough this opening (i.e., tracheostomy tube or a trach tube) toprovide an airway and/or to enable secretions to be removed. Cannulasare also used in a variety of other medical environments.

Illustrative medical systems and processes employing, e.g., cannulas areshown, by way of example, in the following references, the entiredisclosures of which are incorporated herein by reference in theirentireties: U.S. Pat. No. 6,135,110 entitled Tracheostomy Tube; U.S.Pat. No. 6,105,577 entitled Advanced Tracheostomy Tube And OralEndotracheal Tube Holder; U.S. Pat. No. 5,819,723 entitled Methods AndApparatus For Reducing Tracheal Infection; U.S. Pat. No. 5,762,638entitled Anti-Infective And Anti-Inflamatory Releasing Systems ForMedical Devices; U.S. Pat. No. 5,626,132 entitled Tracheal Tube WithBuilt-In Vocalization Capability; U.S. Pat. No. 5,515,844 entitledMethod And Apparatus For Weaning Ventilator-Dependent Patients; U.S.Pat. No. 5,487,383 entitled Tracheal Tube Cuff Inflation Control AndMonitoring System; U.S. Pat. No. 5,230,332 entitled Methods AndApparatus For A Micro-Tracheal Catheter HUB Assembly; U.S. Pat. No.5,217,007 entitled Speculum For Forming An Ostomy In A Trachea; U.S.Pat. No. 5,217,005 entitled Apparatus For Performing PercutaneousTracheostomies And Cricothyoidectomies; U.S. Pat. No. 4,987,895 entitledTracheal Tube; U.S. Pat. No. 4,924,862 entitled Pressure Controller AndLeak Detector For Tracheal Tube Cuff; U.S. Pat. No. 4,817,598 entitledTracheostomy Tube With Ring Pull Removable Inner Cannula; U.S. Pat. No.4,471,776 entitled Static Tracheostomy Tube; U.S. Pat. No. 4,419,095entitled Cannula With Radiopaque Tip.; U.S. Pat. No. 4,315,505 entitledTracheostomy Tube With Disposable Inner Cannula; U.S. Pat. No. 4,235,229entitled Adjustable Tracheostomy Tube Assembly.

Existing cannula systems had a variety of limitations. The presentinvention was made in view of these and/or other limitations in therelated art.

SUMMARY OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention provide substantialimprovements over the above-mentioned and/or other systems and methodsin the related art.

According to some embodiments, a multiple cannula assembly for insertioninto a patient includes: a flexible outer cannula having a proximalhead; a flexible inner cannula having a proximal hub; the inner cannulabeing longitudinally insertable into the outer cannula to an insertionposition with the hub inside the head; the head including at least oneridge and the hub including at least one protrusion, the hub beingrotatable to a locked position with the at least one protrusion underthe at least one ridge upon rotation of the hub within the head from theinsertion position; the head including a connector to connect torespiratory equipment in the locked position. Preferably, the protrusionis locked upon rotation of the hub about ¼ turn clockwise. In someembodiments, the assembly includes an expandable cuff. And, in someembodiments, the outer cannula includes a percutaneous tip. Preferably,the hub includes a knurled portion that extends from the head when inthe locked position.

According to other embodiments, a multiple cannula assembly forinsertion into a patient includes: a flexible outer cannula having aproximal head; a flexible inner cannula having a proximal hub; the innercannula being longitudinally insertable into the outer cannula to aninsertion position with the hub proximate the head; the flexible innercannula being made with PTFE. Preferably, the PTFE includes nodes andfibers. Preferably, the nodes are arranged around a circumference of theinner cannula and/or the fibers are oriented along a length of thecannula.

According to other embodiments, a multiple cannula assembly forinsertion into a patient includes: a flexible outer cannula having aproximal head; a flexible inner cannula having a proximal hub; the innercannula being longitudinally insertable into the outer cannula to aninsertion position with the hub proximate the head; the inner cannulabeing made with a material having fibers oriented along a length of thecannula and nodes around a circumference of the cannula.

According to some embodiments, a multiple cannula assembly for insertioninto a patient includes: a flexible outer cannula having a proximalhead; a flexible inner cannula having a proximal hub; the inner cannulabeing longitudinally insertable into the outer cannula to an insertionposition with the hub proximate the head; the outer cannula including asubstantially rigid tip portion and a substantially flexible portion,the substantially rigid tip portion being made with a rigid PVC materialhaving a shore D hardness of between about 55 to 65 and thesubstantially flexible portion being made with a flexible PVC materialhaving a shore A hardness of between about 80 to 90. Preferably, thesubstantially rigid tip includes a substantially conical front-section,a large-diameter substantially cylindrical mid-section, a downward step,and a small-diameter substantially cylindrical rear-section. In someembodiments, the rigid PVC material has a shore A hardness of more than15 greater than the shore A hardness of the substantially flexibleportion, or, preferably, more than 20 greater than the shore A hardnessof the substantially flexible portion.

The above and/or other aspects, features and/or advantages of variousembodiments will be further appreciated in view of the followingdescription in conjunction with the accompanying figures. Variousembodiments can include and/or exclude different aspects, featuresand/or advantages where applicable. In addition, various embodiments cancombine one or more aspect or feature of other embodiments whereapplicable. The descriptions of aspects, features and/or advantages ofparticular embodiments should not be construed as limiting otherembodiments or the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures are provided by way of example, withoutlimiting the broad scope of the invention or various other embodiments,wherein:

FIG. 1 is a perspective view of an assembly according to someillustrative embodiments of the invention being manipulated via a user'shand;

FIG. 2 is a table depicting some illustrative features according to someillustrative and non-limiting embodiments of the invention;

FIG. 3(A) is a top view of an assembly including an outer cannula havingan attached head and an inflatable cuff according to some illustrativeembodiments of the invention, FIG. 3(B) is a cross-sectional view of theassembly shown in FIG. 3(A) taken along the line 3B-3B′ shown in FIG.3(A), and FIG. 3(C) is a cross-sectional view of the assembly shown inFIG. 3(A) taken along the line 3C-3C′ shown in FIG. 3(B).

FIG. 4 is a plan view of a neck strap according to some illustrativeembodiments of the invention;

FIG. 5(A) is an end view of a hub that can be attached to an innercannula in some illustrative embodiments, FIG. 5(B) is a perspectiveview of the hub shown in FIG. 5(A), and FIG. 5(C) is a cross-sectionalview of the hub shown in FIG. 5(A), attached to an inner cannula, andtaken along the line 5C-5C′ shown in FIG. 5(A).

FIG. 6(A) is a front view of a head that can be attached to an outercannula in some illustrative embodiments, FIG. 6(B) is a cross-sectionalside view of a connector portion of the head shown in FIG. 6(A) takenalong the line 6B-6B′ shown in FIG. 6(D), FIG. 6(C) is a side view ofthe head shown in FIG. 6(A) from substantially perpendicular to the viewshown in FIG. 6(A), and FIG. 6(D) is a top view of the connector portionof the head shown in FIG. 6(A) looking downward into the head in FIG.6(A).

FIG. 7 is a perspective view of a multiple cannula assembly according tosome illustrative embodiments of the invention including a stiffened tipportion;

FIG. 8 is a perspective view showing an outer cannula including astiffened tip portion as shown in FIG. 7;

FIG. 9 is a perspective view of an obsturator according to someillustrative embodiments of the invention; and

FIG. 10 is a magnified cross-sectional photograph depicting the materialof the inner cannula according to some illustrative embodiments of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In some preferred embodiments, a multiple cannula system is providedthat includes an outer cannula and a substantially co-axial innercannula. Preferably, the outer cannula is an arcuate shaped flexibletube with a disposable inner cannula. In the most preferred embodiments,the multiple cannula system is a tracheostomy tube system. However,various embodiments and/or aspects of various embodiments can involvemultiple cannula assemblies for other purposes and/or environments.

In some embodiments, the system can include a percutaneous tracheostomytube structure. In addition, in some embodiments, the system can includean expandable (e.g., inflatable) cuff. In some examples, cuffed productscan be used with percutaneous dilatational tracheotomy (PDT) procedures.In various embodiments, the assembly can incorporate features (such as,e.g., materials, etc.) of existing cannula tube systems and methods,such as, e.g., that set forth in the above-noted patents incorporatedherein by reference.

Preferably, the device can be placed in a patient surgically and/orpercutaneously in, e.g., an acute care setting. In some embodiments, thetracheostomy tubes are generally temporary and provide a method forventilation that can be, e.g., more comfortable and less problematicthan long-term endotracheal intubation. The tracheostomy tubes canpreferably provide an artificial airway that will improve airway accessfor clearing secretions, permitting voice restoration and/or improvingpulmonary status by reducing the work of breathing and/or loweringphysiological dead-space. In various embodiments, the device can be usedto provide an artificial airway in order to assist in the treatment of avariety of respiratory diseases and/or in airway management forpatients.

In some embodiments, the devices can be implemented by ear-nose-throatspecialist physicians (ENTs) and/or any other physicians performingsurgical and/or percutaneous tracheostomy procedures. The product can beused, e.g., with critically ill and/or injured patients that require,e.g., substantially long-term security of their airway and/orsubstantially long-term ventilation.

In some embodiments, a variety of tracheostomy tube systems can beprovided having different sizes. For example, sizes can range, in someembodiments, between about sizes of 6, 7, 8, 9 and 10 mm for the insidediameter (I.D.) of an outer cannula (not including, e.g., cufffeatures). In some embodiments, a tracheostomy tube system can includeone or more of the following features:

-   -   a flexible outer cannula with a flexible disposable inner        cannula;    -   the outer cannula can be cuffed or uncuffed;    -   the outer cannula can include a percutaneous tip (which can be        made, e.g., compatible with a percutaneous dilatational loading        dilator) or a dilatational tracheostomy (PDT) style tip; and/or    -   a cuff pressure indicator (CPI)(in some embodiments, the        assembly can employ, by way of example, one or more of the        indicator devices shown in U.S. Pat. Nos. 4,074,714, 4,116,201        or 4,133,303 of The Kendall Company).

Preferably, the system is based on a modular product platform. Forexample, the product design can be modular in nature. A modular designplatform can allow, e.g., the manufacture of many different but specificend design product configurations. In preferred embodiments, the innerand outer cannulas are bendable and flexible.

In some embodiments, the product can be packaged as follows: individualassemblies can be packaged in, e.g., trays, while a plurality of trayscan be packaged together as a unit in a carton. Preferably, disposableinner cannulas are packaged in trays, while, for example, about ten suchtrays can be packaged in a carton. In preferred embodiments, additionaldisposable inner cannulas can be purchased separately.

In some embodiments, the product is provided to the customer in asterile condition (e.g., in a sterile package). In some examples, themethod of sterilization can include ethylene oxide (EtO) gassterilization. In some embodiments, the device is used for only a singlepatient and/or a single use.

In preferred embodiments, the materials used will perform appropriatelyafter exposure to at least some, preferably all, of the followingchemical/cleaning agents: isotonic saline solution; water solublelubricants or gels; typical disinfectant solutions; isopropyl alcoholand water. In preferred embodiments, the materials used will performappropriately after repeated exposure to common respiratory drugaerosols including: bronchodilators; steroids; mucolytics; surfactants;antibiotics; and/or their related gas and/or liquid propellants(perflourocarbons [CFCs and CFC-free PFCs], methanes, alcohols, etc.).In preferred embodiments, the materials used shall perform appropriatelyduring and after exposure to conventional anesthetic gases in clinicallyexpected concentrations including, e.g.: flourane and/or halothane. Inpreferred embodiments, the materials used shall pass ISO 10993-1biological safety tests appropriate for their intended use. In preferredembodiments, the materials used and the packaging shall be Latex free.

FIGS. 1-9 show some illustrative embodiments of the invention. In thisregard, FIG. 1 shows a tracheostomy tube assembly including, an outercannula 30 having a head 60 fixed at a proximal end, an inner cannula 55(shown in dashed lines) having a hub 50 fixed at a proximal end (the hub50 shown protruding slightly from the head 60); a neck flange 40; aninflatable cuff 30C; and a pilot balloon 100 for inflating theinflatable cuff. While a wide variety of embodiments are encompassed bythis disclosure, in some illustrative embodiments, the parts can be madesubstantially in proportion to that shown in the figures. For example,in some embodiments, the parts can be made substantially as shown in oneor more of the FIGS. 1-9, with such figures being proportional and toscale as shown in various illustrative and non-limiting embodiments ofthe invention.

FIG. 2 is a table depicting some illustrative and non-limiting examplesof dimensions for an outer cannula in some illustrative embodiments ofthe invention, including product sizes 6-10, having respective insidediameter (I.D.) in millimeters, outside diameter (O.D.) in millimeters,and lengths in millimeters. FIG. 2 also depicts some illustrativedimensions of the cuff in a resting condition along with inflationvolumes in the illustrative embodiments shown. It should be understoodthat these illustrative embodiments are merely illustrative and do notlimit the wide range of the various embodiments that may be constructed.

Outer Cannula

In some preferred embodiments, the outer cannula is a generally flexibletube. Preferably, the outer cannula has a generally constantcross-sectional shape. The outer cannula can be constructed of a varietyof materials. In some preferred embodiments, it can be constructed with,for example, a flexible polyvinyl chloride (PVC). In some embodiments,the outer cannula can be manufactured in a variety of sizes, such as, byway of example only, 6.0, 7.0, 8.0, 9.0 and 10.0 mm internal diametersizes as shown in FIG. 2. In some embodiments, the outer cannula can besubstantially clear with, e.g., a radio opaque portion(s) or line(s).Preferably, the outer cannula 30 is made with biocompatible materials.In some embodiments, the cannula 30 can be made with a material having aShore A Hardness of about between about 70 to 100, or, more preferably,between about 75 to 95, or, more preferably, between about 80 to 90, or,more preferably, between about 82 to 88, or, more preferably, about 85.In some preferred embodiments, the outer cannula 30 has a Shore AHardness of 85 plus-or-minus 3.

In the most preferred embodiments, the outer cannula 30 is formed byextrusion. For example, the outer cannula can preferably be formed bythe forcing of softened polymeric material through the orifice of a dieto produce a continuous product of a controlled cross section, using anextruder.

As shown in FIGS. 3(B) and 3(C), the cannula 30 preferably includes alarge substantially circular internal lumen 30L that, among otherthings, receives the inner cannula 55 (as described below) and a smallairway lumen 30 l that extends inside a length of the wall of thecannula 30 between an air inlet 30 i and a cuff inlet 30Ci tosupply/return air to/from the cuff 30C. Preferably, the lumen 30 l doesnot communicate with the lumen 30L (e.g., such that air within the lumen30 l will not enter the lumen 30L). As shown in dashed lines in FIG.3(B), the line 30CL can be connected to the inlet 30 i to supply airtherein. In some embodiments, the lumen 30 l can be formed duringextrusion and, then, after extrusion inlets 30 i and 30Ci can be formed(e.g., by cutting) and the lumen 30 l can be sealed at proximal anddistal ends to provide a sealed air passage. In some embodiments, thelumen 30 l can be formed after extrusion of the cannula. Of course,while extrusion is preferred, the cannula can be formed using numerousother methods (such as, e.g., various molding methods).

In some embodiments, as shown in FIGS. 3(A) and 3(B), the outer cannulahas a head 60 fixed thereto. Preferably, the head includes a connectorportion 61 and a base portion 62. In some illustrative embodiments, theconnector 61 can be a 15 mm connector (e.g., the diameter D, shown inFIG. 6(C), can be, e.g., about 15 mm or about 0.599 inches in someillustrative embodiments). Preferably, the head 60 is bonded securely tothe outer cannula 30 via the base portion 62 and does not detach undernormal use conditions. In some embodiments, the base portion 62 and theconnector portion 61 can be integrally formed together (e.g., as asingle, integrally molded piece). In some embodiments, the base portion62 and the connector portion 61 can be welded and/or otherwise connectedtogether (such as, e.g., via ultrasonic welding). In some embodiments,the head 60 can be molded to and/or integrally formed with the outercannula 30. Preferably, the base 62 of the head includes two lockingdetentions or holes 62H, shown in FIG. 6(A)), for receiving arms 40Fextending from the flange 40 so as to retain the flange 40 in a pivotingand/or swiveling manner on the head base. Preferably, the head base alsoincludes a seat 62S for a hub of the inner cannula. In some embodiments,the head (including the base 62 and/or the connector 61) can be formedwith, e.g., acrylonitrile butadiene styrene (ABS). In some embodiments,the head can be colored, such as, e.g., white.

As shown in FIG. 3(B), the base 62 preferably includes a seat 62S (suchas, e.g., including a conical surface as shown), an outer dependingcylindrical extension 620, an inner depending cylindrical extension 621,and a cylindrical recess or groove 62R between the outer and innerextensions 620 and 621. As shown in FIG. 3(B), a proximal end of theouter cannula 30 can be received in the cylindrical recess 62R forattachment thereto. Preferably, in embodiments having an inner extension621, the extension 621 has a thin cross-sectional width so as tominimize interference during insertion of an inner cannula and tomaximize the size of the inner cannula that can be inserted. Forexample, in some illustrative and non-limiting embodiments that can beused with products listed in FIG. 2, the width of the extension 621 ispreferably less than about 0.03 inches, or, preferably, about 0.027inches or less.

Different Flexibilities

In some embodiments, the outer cannula 30 can include portions withsubstantially different flexibilities (such as, e.g., substantiallydifferent durometer characteristics). In general, it can be desirable tohave a trach tube that is flexible so as to enable it to bend and curveto different physiologies such that it can be inserted into a widevariety of patients relatively easily. However, in some instances, whenthe end of the outer cannula is very flexible, insertion into the airwaycan be somewhat difficult.

In some embodiments, the outer cannula is formed with an end portionthat includes a material that is substantially stiff (e.g.,substantially rigid). As shown, for example, in FIGS. 7-8, an outercannula can include an end portion 70 that is made with a substantiallystiff material and which is attached to a portion 30′ that is made of asubstantially flexible material at a junction 71. For example, thecannula portion 30′ can be made with materials like that used for thecannula 30 described in various embodiments herein. In some embodiments,the materials can be bonded together using an RF welding process. Forexample, in some embodiments, the materials can be bonded together usingone or more materials and/or processes described in U.S. Pat. No.4,419,095, the entire disclosure of which is incorporated herein byreference. In some embodiments, the materials are bonded together bycontinuous extrusion of two different and mutually chemically compatibleelements. For example, in some embodiments, the materials can be bondedtogether using one or more materials and/or processes described in PCTInternational Publication No. WO 97/37702, published Oct. 16, 1997,entitled Bronchoaspiration Tube Having Soft And Hard Portions, theentire disclosure of which is incorporated herein by reference. Inillustrative embodiments employing an extrusion, the tip and cannula 30′portions would be made with substantially continuous cross-sections, butcould be, e.g., modified after extrusion (if desired).

In some embodiments, the tip portion 70 has a Shore D hardness of about50 to 70, or, more preferably, about 55 to 65, or, more preferably,about 60. In some illustrative embodiments, the tip portion 70 has aShore D hardness of about 60 plus-or-minus 2. In some illustrativeembodiments, the tip portion 70 can have a Shore A hardness of about 105to 115. In some embodiments, the tip portion 70 can be made with a rigidPVC.

In some embodiments, the cannula portion 30′ can be made with a materialhaving a Shore A Hardness of about between about 70 to 100, or, morepreferably, between about 75 to 95, or, more preferably, between about80 to 90, or, more preferably, between about 82 to 88, or, morepreferably, about 85. In some preferred embodiments, the outer cannulaportion 30′ can have a Shore A Hardness of 85 plus-or-minus 3.

In some embodiments, the tip 70 can have a total length of between about0.4 to 0.8 inches, or, preferably, about 0.6 inches. In someembodiments, the tip can have a wall cross-sectional width d1 that isabout equal to the cross-sectional width of the cannula 30′ such as,e.g., comparable to the embodiments shown in FIG. 2 in some illustrativecases (e.g., wherein O.D. minus I.D. multiplied by ½ equals thecross-sectional wall width).

In tests of some preferred embodiments, strengths of parts of the deviceaccording to some embodiments have been found to withstand separationforces of well over 11 lbs, such as, e.g., well over about 20 lbs, andeven over about 40 lbs, and even over about 60 lbs of force in someembodiments. Here, separate forces include longitudinal forces appliedbetween the tip 70 and the portion 30′.

Stepped Portion

In some embodiments, the outer cannula includes a downward step portion72 as shown, by way of example, in FIGS. 7-8. Although FIGS. 7-8 depictembodiments with a stiffer tip 70, a stepped portion 72 could also beapplied in embodiments which do not include such a stiffer tip 70.

Among other things, the stepped portion can most advantageously be usedin conjunction with embodiments including a cuff. In this regard, whenthe cuff is formed around the outer cannula, an outwardly bulge orshoulder created by the cuff can be substantially or entirelyeliminated. In this manner, the device can, e.g., be more easilysurgically or percutaneously inserted into a patient with a very lowforce/insertion force. In some embodiments, the stepped portion 72extends inward about 0.01 to 0.02 inches, or, more preferably, about0.013 to 0.017 inches, or, preferably, about 0.015 inches.

Inner Cannula

In some embodiments, a flexible inner cannula 55 is included.Preferably, the inner cannula 55 is disposable and/or replaceable. Inthat regard, the inner cannula is preferably designed to be easilyremoved from the outer cannula 30. Preferably, the inner cannula 55 issufficiently flexible to accommodate the shape of the outer cannula intowhich it is placed with a low insertion force and/or with a low removalforce. The inner cannula preferably does not kink during use. Inaddition, the inner cannula 55 preferably has a length thatsubstantially matches the length of the outer cannula at its distal tip(i.e., the end of the inner cannula 55E, see FIG. 5(C), is preferablycommensurate with the end of the outer cannula). In some embodiments,alignment members and/or marks M1, M2, such as shown in, e.g., FIGS.5(A) and 6(D), can be provided on the inner and outer cannula connectorsto help depict when they are locked (see below regarding connectionprocess steps).

In the most preferred embodiments, the inner cannula 55 is also formedby extrusion. Once again, such extrusion can include, e.g., the forcingof softened polymeric material through the orifice of a die to produce acontinuous product of a controlled cross section, using an extruder. Ofcourse, while extrusion is preferred, the cannula can be formed usingnumerous other methods (such as, e.g., various molding methods).

In some preferred embodiments, the inner cannula includes a hub 50 fixedto its proximal end. In some embodiments, the hub includes a twist-lockconnector that secures inside a respective connector in the outercannula (such as, e.g., within a 15 mm connector on the tracheostomytube). Preferably, the hub 50 includes a ridged or knurled portion 50Kso as to facilitate manual operation (e.g., rotation) of the hub 50 suchas shown in FIG. 1. In addition, the hub 50 preferably includes aplurality of protrusions 50P that are configured to lock under thelocking members 61R on the head shown in FIGS. 3(B), 6(B) and 6(D) wheninserted past the locking members and rotated to a position under thelocking members. Preferably, the protrusions 50P have a rounded topsurface to facilitate entry under the members 61R during this rotation.In preferred embodiments, the protrusions 50P can slide under themembers 61R into a recess 61RR of the head adjacent an end stop 61S thatabuts the protrusions 50P to prevent further rotation.

In some preferred embodiments, the tube 55 can be formed with apolytetrafluoroethylene (PTFE) material. The tube can, in someembodiments, be colored, such as, e.g., white. In some embodiments, thehub can be made with a variety of appropriate materials, such as, e.g.,polymer materials that are substantially rigid. In some illustrativeembodiments, the hub can have a color, such as, e.g., white. In somepreferred embodiments, the hub can be bonded to the inner cannula usingan overmolding process. Preferably, the hub is adapted to lock the innercannula within the outer cannula.

In some embodiments, the inner cannula is made with a high densityporous expanded PTFE (ePTFE). For example, in some embodiments, thedensity can be about 1.2+0.0−0.1 g/ccm. In other illustrativeembodiments, the density can vary from the above by about, for example,plus-or-minus 5%, or, in other embodiments, about plus-or-minus 10%, or,in other embodiments, about plus-or-minus 25%, or, in other embodimentseven more.

In some embodiments, the inner cannula has a substantially constantcross-sectional shape as is substantially cylindrical with open ends ondistal and proximal ends. In some embodiments, the ends of thecylindrical cannula are approximately at about an 85 to 95 degree angle,preferably about a 90 degree angle, to the length of the inner cannula(e.g., when the cannula, which is preferably flexible, is arranged suchthat its length is along a substantially straight line).

In some illustrative embodiments, the inner cannula can have a wallthickness of between about 0.01-0.02 inches, or, more preferably,between about 0.014-0.018 inches, or, more preferably, between about0.0145-0.0175 inches, or, more preferably, about 0.016 inches. In someillustrative and non-limiting embodiments, respective inner cannulasusable with the illustrative outer cannula product sizes 6, 7, 8, 9 and10 in FIG. 2 can have inner diameters of, e.g., about 0.186, 0.226,0.265, 0.298, and 0.338 inches, respectively. In some illustrative andnon-limiting embodiments, respective inner cannulas usable with theillustrative outer cannula product sizes 6, 7, 8, 9 and 10 in FIG. 2 canhave outer diameters of, e.g., about 0.218, 0.258, 0.297, 0.336, and0.376 inches (plus-or-minus about 0.005 inches), respectively.Similarly, in some illustrative and non-limiting embodiments, respectivehubs 50 usable with the product sizes 6, 7, 8, 9 and 10 in FIG. 2 canhave, by way of example: dimensions W of about 0.226, 0.265, 0.304,0.344, 0.384 inches, respectively; dimensions WO of about 0.5-0.65inches, or, more preferably, about 0.58 inches; dimensions H1 of about0.15 inches; dimensions H2 of about 0.35 inches, respectively; and, anangle Θ of about 45 degrees. In some illustrative embodiments, the hub50 can have dimensions substantially as shown in FIGS. 5(A), 5(B) or5(C), with such figures being shown to scale in some illustrative andnon-limiting embodiments.

In some embodiments, the inner cannula can be opaque. In some preferredembodiments, the inner cannula can be configured to lock into a 15 mmconnector on an outer tracheostomy cannula. In this manner, the 15 mmconnector can be readily adapted for use with standard respiratoryequipment.

In some preferred embodiments, TEFLON is used for the inner cannula. TheTEFLON inner cannula can be used, in some embodiments, to improve theI.D./O.D. ratio of the tracheostomy tube. Among other things, TEFLON canbe advantageous since it can slide in and out of the outer cannularelatively well which can allow the inner cannula outside diameter to beas large as possible which allowing for maximum movement of air. Thisimproved I.D./O.D. ratio can be used to improve airflow through the tubewhen the inner cannula is in place. The improved airflow can providelower airway resistance and reduced work required during breathing. Inaddition, reducing airway resistance can also enhance a weaning processwith an improvement in patient acuity and a reduction in the length ofstay (LOS) in acute care.

In addition, TEFLON can be used to reduce the propensity of viscoussecretions adhering to an inner wall of the inner cannula. A reductionin secretion adherence can, among other things, help to diminish I.D.reduction due to secretions (e.g., clogging). In this regard, when theairway is properly humidified and the patient is properly hydrated,patient secretions can have a lower affinity for adherence to the TEFLONinner cannula.

In the more preferred embodiments, the material of the inner cannula ismade with a porous polytetrafluoroethylene (PTFE). In some embodiments,the material can be made using at least some, preferably all, of thefollowing steps:

-   -   Granulating: the material preferably begins as a granulated        powder.    -   Mixing: the powder is preferably mixed with, e.g., an ultrapure        mineral spirit that serves as a lubricant during extrusion.    -   Compressing: the mixture is preferably compressed into a charge.    -   Loading: the charge is preferably loaded into an extruder (in        some preferred embodiments, the extruder is a horizontal        extruder design).    -   Extruding: concentricity is preferably achieved by carefully        lining up the tooling of the extruder. A die and a mandrel can        be attached. The extrudate can be collected.    -   Evaporating: plugs can be attached to the ends and the mineral        spirits can be evaporated off.    -   Stretching & Sintering: the material is then preferably        stretched in an oven. Then, the material is preferably heated        above its melting point (e.g., sintered). The material        properties can be solidified during the sintering phase of the        process.    -   Annealing: the airway tube is preferably then subjected to an        annealing process. The annealing process can, e.g., ensure that        the material remains round after processing.

In preferred embodiments, the process creates a unique structure ofnodes N and fibers F, such as depicted in the magnified photograph shownin FIG. 10. Preferably, the nodes are arranged around the circumferenceof the tubing and the fibers are oriented along the length of thetubing. In preferred embodiments, this structure allows the material tocompress and flex without a significant change in the outer diameterand/or the cross-sectional area. In some embodiments, this can occurbecause the fibers collapse between the nodes. In this manner,structural integrity of the tubing can be achieved through, e.g., suchan arrangement of nodes and fibers, with the nodes providing supportaround the wall of the tubing making it difficult to collapse.

Among other things, the node and fiber structure facilitates connectionof the hub 50 to the inner cannula 55. In this regard, an overmoldprocess is preferably used. While achieving a connection to a TEFLONmaterial could otherwise be difficult because it can be difficult toform a strong hold to the TEFLON, the node and fiber structure enhancesthe ability of the hub to connect to the cannula 55—such as, e.g., byproviding a surface to which the hub can connect and bond to.

In preferred embodiments, the inner cannula is constructed such thatwhen the cannula is bent (such as, e.g., during use), the inner cannuladoes not fold, block and/or restrict the airway there-through. Amongother things, the preferred materials of the inner cannula describedherein can advantageously substantially maintain the diameter and/or thecross-sectional area of the inner cannula even during bending. Forexample, the cross-sectional area of the inner cannula can be maintainedsubstantially constant even when bent within an angle and arc similar tothat shown, e.g., in FIG. 3(B) (for example, the angle can be, e.g.,about 95, 100, 105 or 110 degrees in some embodiments and the arc canhave a radius of curvature of about 1.5 to 2 inches in some embodiments,or, as some examples, about 1.664, 1.765, 1.793 or 1.821 inches).

Neck Flange

In some embodiments, the device includes a pivotally or swivelly mountedneck flange 40, best shown in FIGS. 1 and 4, that provides conformity tofit onto individual neck anatomies. In some embodiments, the neck flange40 can be provided with tie strap holes 40H for attachment to a tiestrap 40T. The tie strap can be, e.g., configured to strap around thepatient's neck and may include means to adjust the length, to separatevia a buckle and/or clip and/or the like. Preferably, the neck flange 40is configured to pivot or swivel relative to the outer cannula 30. Therange of pivoting or swiveling can be selected depending oncircumstances. Preferably, the neck flange is flexible such that it canconform to the contour of an individual patient's neck during use. Inpreferred embodiments, the neck flange remains in a substantially fixedcondition relative to a length of the outer cannula (e.g., in preferredembodiments, it is not longitudinally adjusted along the length of thecannula). Preferably, the neck flange 40 has sufficient integrity toprevent material failure during bending, flexing and/or stress underproper and intended use conditions.

In some embodiments, the neck flange includes an inner ring 401 (shownin dashed lines in FIG. 4) and an outer ring 40R. In some embodiments,the inner ring 401 can be made with a clear polycarbonate material, andthe outer flange 40R can be made with a clear PVC material. In somepreferred embodiments, the neck flange 40 includes printing 40P thereonrelated to the product, such as, e.g., product name, I.D., O.D., lengthand/or style information and/or other information. When such an innerring 401 is used, the outer ring is preferably fixed thereto, such asusing an overmold process. In various embodiments, the neck flange doesnot include inner and outer rings, but is formed as a single unitarilymolded member 40.

Cuff

In some embodiments, the outer cannula includes a cuff 30C. A cuff canbe provided, when desired, on models that include a percutaneous tipand/or on models without a percutaneous tip. The cuff is preferably athin-wall, high-volume and/or low-pressure cuff to minimize trachealpressure. Preferably, when inflated, the cuff conforms to the naturalshape of the trachea providing a seal at low intracuff pressure. In someembodiments, the cuff can be made of a transparent material. In someillustrative embodiments, it can be made with a plastisol material. Insome illustrative and non-limiting embodiments, the cuff can includeproperties as shown in the illustrative table of FIG. 2.

In some embodiments, a cuff inflation line 30CL, such as, e.g., thatshown in FIG. 1, preferably includes a luer valve with an integral pilotballoon 100 to effect cuff inflation. In some embodiments, a cuffpressure indicator (CPI), such as, e.g., CPI 110 shown in FIG. 7, isprovided to indicate to a clinician when the cuff is inflated to asufficient pressure after the trach tube is inserted. In some preferredembodiments, the pressure indicator provides a visual display such as,e.g., a digital display, a mechanical display (e.g., a needle, dial,etc.) and/or another display. For example, the cuff pressure indicatorcan include, e.g., a valve, a pilot balloon, connector tubing (e.g.,made with PVC or the like). In some embodiments the cuff pressureindicator can have an operating pressure of about 15-25 cm of H₂O.

In some embodiments, during use, to ease insertion during surgicaltracheotomy and to guard against cuff perforation from sharp edges of,for example, cartilage, the cuff can be tapered back. For example, thiscan be accomplished by first inflating the cuff and moving the cuff awayfrom the distal tip of the outer cannula towards the swivel neck platewhile the residual air is removed by deflation.

Disposable Cap

In some embodiments, a disposable cap (not shown) can also be used toocclude a proximal end of a cuffless tracheostomy tube such that thepatient breathes around the outer diameter of the tube and through theupper airway tract during the weaning process.

In some embodiments, disposable caps can be made available (e.g., sold)in a variety of sizes that correspond to various available cannula sizesof cuffless disposable cannula tracheostomy tubes and can be purchasedseparately.

Percutaneous

In some embodiments, the device can be used in conjunction with apercutaneous dilatational tracheotomy (P.D.T.) and can be inserted intothe patient using, for example, an appropriate loading dilator providedwith a percutaneous dilatational kit, such as, e.g., any appropriate kitknown in the art. For example, a percutaneous kit can include, amongother things, e.g., a rod-like introducer that is used to create a holein a patient's neck.

In some percutaneous embodiments, an outer cannula includes a rigid tip,such as, e.g., a rigid tip similar to that shown in FIGS. 7-8.Additionally, while FIGS. 7-8 show a rigid tip with a stepped portion,as should be understood based on the above, a stepped portion can beomitted in various embodiments.

Obturator

In some preferred embodiments, a tracheostomy tube assembly includes anobturator as shown in FIG. 9. An obturator can be used, e.g., to helpinsert the outer cannula into a patient in, e.g., non-percutaneousembodiments. For instance, the obturator can be initially inserted intothe outer cannula during insertion and then removed. In some instances,an obturator can be stored in an accessible location near the patientfor use during an unscheduled reintubation. Preferably, the obturatorincludes a smooth, rounded-tip that facilitates insertion. Preferably,the obturator is easy to insert and remove. Preferably, the obturatordoes not come out of the outer cannula in a manner to fall out under itsown weight if the tube is in an inverted position. Preferably, theobturator does not recess into the outer cannula beyond its tolerancelimit when insertion forces are applied to its distal tip while itsproximal end is being held securely against the head assembly of theproduct. In some illustrative and non-limiting embodiments usable withproducts 6, 7, 8, 9, and 10 shown in FIG. 2, the obturator can have alength OL of about 3.866, 4.205, 4.345, 4.595, or 4.615 inches,respectively. In use, the physician can, e.g., grasp the obturator atthe base OB. Preferably, the obturator includes an identificationmarking OM designating the size or other characteristics (e.g., aproduct size 6 being shown in the illustrated example).

In some illustrative embodiments, the obturator can be made with ahigh-density polyethylene (HDPE).

Other Features

In some embodiments, the tracheostomy tube system can also include someor all of the following additional features:

-   -   speaking and/or weaning means: such as, e.g., facilitating the        administration of oxygen to be passed up the trachea across the        vocal chords; and/or including fenestrations in the outer and/or        inner cannula to facilitate speaking and/or weaning;    -   anti-microbial means: such as, e.g., an anti-microbial coating        to reduce bacterial colonization;    -   evacuation means: such as an evacuation means (EVAC) that, e.g.,        facilitates the removal of, e.g., subglottic secretions which        can pool above, e.g., a tube's cuff.        Illustrative Methods of Use (e.g., Surgical)

In some illustrative embodiments, methods of use can include at leastsome, preferably all, of the below-listed steps.

Step 1: Tube Insertion:

Initially, a physician can select an appropriate tracheostomy tubeassembly size. Preferably, the obturator is inserted into the outercannula. The obturator preferably is fully seated before the tube isinserted into the patient. In some instances, a thin film ofwater-soluble lubricant can be applied to the outer cannula, cuff and/orprotruding portion of the obturator to facilitate insertion.

Before insertion, the physician will preferably perform a surgical orP.D.T. tracheotomy procedure. Then, the tracheostomy tube (i.e., theouter cannula) can be inserted into the patient's trachea with theobturator inside the tracheostomy tube. After the outer cannula isproperly in place, the physician preferably removes the obturatorpromply.

Then, the physician preferably inserts the disposable inner cannula intothe outer cannula. Upon full insertion, the physician preferably locksthe inner cannula in an inserted position by turning the inner cannula(such as, e.g., depicted in FIG. 1). For example, in some preferredembodiments, the inner cannula can be locked with two motions: 1)inserting the inner cannula to an insertion position; and 2) rotatingthe inner cannula to a locked position from the insertion position.Preferably, the inner cannula is locked upon a rotation of less thanabout 180 degrees, or, more preferably, less than about 135 degrees, or,more preferably, about 90 degrees or less. Preferably, the inner cannulais locked upon a rotation of between about between about 10 degrees to170 degrees, or, more preferably, between about 45 degrees and 135degrees, or, more preferably, between about 70 degrees and 110 degrees,or, more preferably, about ¼ turn or about 90 degrees. Preferably, thecannula locks in place upon a clockwise rotation and is released upon acounterclockwise rotation, such as, e.g., shown in FIG. 1.

Step 2: Cuff Inflation:

In embodiments having an inflatable cuff, the operation can be asfollows. The cuff can preferably be inflated by injecting air into aluer valve of the inflation line using, for example, a hand-operatedsyringe (not shown).

Preferably, selection of cuff inflation and/or deflation procedures canbe chosen at the discretion of the physician based on circumstances.

Step 3: Securement of Tube:

In some embodiments, the tracheostomy tube assembly can be secured to apatient using a neck strap. In preferred embodiments, a neck strap willbe provided with an initial assembly kit.

Step 4: Cuff Deflation:

In some embodiments having an inflatable cuff, accumulated secretionsabove the cuff are evacuated by, e.g., suctioning before deflating thecuff, unless, e.g., suctioning is contraindicated.

Preferably, to deflate the cuff, the physician withdraws the air slowlyfrom the luer valve of the inflation line using, e.g., a syringe (notshown).

Step 5: Using a Disposable Cap:

In some embodiments, a disposable cap (not shown) can be used.Preferably, the cap has a universal size that can be used with variousmodel sizes. The cap preferably occludes the proximal end of the outercannula, forcing the patient to breathe through the patent's upperairway tract. In this manner, this can help to establish the patency ofthe patient's upper airway tract. Preferably, the patient's airway iscleared by coughing and/or suctioning before capping the tracheostomytube.

In some embodiments, to apply the cap, the physician pushes it securelyover, e.g., a 15 mm connector.

In some embodiments, if a patient is to be mechanically ventilated, thecap can be removed, and the device can be connected to a ventilator.

Step 6: Removing the Inner Cannula:

In some embodiments, the inner cannula can be removed and/or replaced asfollows. Preferably, the disposable inner cannula can be removed bymanually rotating the inner cannula hub about ¼ turn counterclockwise(such as, e.g., shown in FIG. 1) and, then, manually pulling it outward.

Preferably, after the inner cannula has been removed, it can be replacedwith a new inner cannula. If desired, a ventilator can then be connectedto provide or reestablish ventilation. In embodiments having aninflatable cuff, before removing the outer cannula tracheostomy tube,the cuff is preferably substantially completely deflated (such as, e.g.,using a syringe). This can help to ensure, e.g., that the cuff passesthrough the stoma with minimal resistance.

Illustrative Percutaneous Methods

In some embodiments, the device can be configured for percutaneous use.In this regard, for example, the tracheostomy tube can be used, e.g., inconjunction with P.D.T. Accordingly, sterile techniques can be followedfor the handling and placement of the tracheostomy tube.

In some illustrative embodiments, methods of use can include at leastsome, preferably all, of the below-described steps.

In some embodiments, a tracheostomy tube loading dilator can be insertedinto the outer cannula such that a tapered section of the loadingdilator clears the distal tip of the tracheostomy tube (such as, e.g.,by a few centimeters). In some instances, a film of water-solublelubricant can be applied to the outer cannula, a cuff (when present) anda protruding portion of loading dilator to facilitate insertion. Asdiscussed above, a tracheostomy tube loading dilator is part of apercutaneous dilatational kit as known in the art. The physician canthen perform the dilatational tracheotomy procedure and can insert thetracheostomy tube in accordance with the P.D.T. procedure.

After the physician verifies a secure airway, the physician preferablyinserts and locks the inner cannula. In some embodiments, a breathingapparatus can be attached to the tracheostomy tube and the cuff can beinflated as set forth below.

In preferred embodiments, using aseptic non-contaminating techniques,the inner cannula can be inserted into position. In some instances, theinner cannula can be moistened with, e.g., sterile saline to facilitateinsertion.

Broad Scope of the Invention

While illustrative embodiments of the invention have been describedherein, the present invention is not limited to the various preferredembodiments described herein, but includes any and all embodimentshaving modifications, omissions, combinations (e.g., of aspects acrossvarious embodiments), adaptations and/or alterations as would beappreciated by those in the art based on the present disclosure. Thelimitations in the claims are to be interpreted broadly based on thelanguage employed in the claims and not limited to examples described inthe present specification or during the prosecution of the application,which examples are to be construed as non-exclusive. For example, in thepresent disclosure, the term “preferably” is non-exclusive and means“preferably, but not limited to.” Means-plus-function orstep-plus-function limitations will only be employed where for aspecific claim limitation all of the following conditions are present inthat limitation: a) “means for” or “step for” is expressly recited; b) acorresponding function is expressly recited; and c) structure, material,or acts that support that structure are not recited.

What is claimed is:
 1. A method for using an insertable multiple cannulaassembly, the method comprising: positioning an outer cannula, the outercannula having a tip including a stepped portion configured to reduce anoutward bulge of a cuff coupled to the outer cannula; positioning aninner cannula at least partially within the outer cannula; connectingthe inner cannula relative to the outer cannula; and inflating the cuffcoupled to the outer cannula.
 2. A method according to claim 1, whereinconnecting the inner cannula relative to the outer cannula includesrotating the inner cannula relative to the outer cannula from anunlocked position to a locked position.
 3. A method according to claim1, wherein connecting the inner cannula relative to the outer cannulaincludes rotating a hub of the inner cannula relative to a head of theouter cannula from an unlocked position to a locked position in which atleast one protrusion of the inner cannula hub is engaged with at leastone ridge of the outer cannula head.
 4. A method according to claim 1,wherein the outer cannula tip is substantially rigid.
 5. A methodaccording to claim 1, wherein the outer cannula tip includes a taperedportion extending from a first end having a first outer diameter to asecond end having a second outer diameter larger than the first outerdiameter, and a cylindrical portion having a third outer diameter,wherein the stepped portion is defined by a difference between thesecond outer diameter and the third outer diameter.
 6. A methodaccording to claim 5, wherein the tapered portion and the cylindricalportion of the outer cannula tip have a constant inner diameter.
 7. Amethod according to claim 1, wherein both the inner cannula and theouter cannula arc substantially flexible.
 8. A method for using amedical cannula, the method comprising: inserting at least a portion ofa substantially flexible cannula assembly into a patient, the cannulaassembly including (a) and outer cannula having an outer cannula body,an inflatable cuff coupled to the outer cannula body, and a steppedportion configured to reduce an outward bulge of the cuff relative tothe outer cannula body and (b) a retractable inner cannula inserted atleast partially within and locked to the outer cannula; and afterinserting the cannula assembly including the outer cannula and innercannula, inflating the cuff coupled to the outer cannula body.
 9. Amethod according to claim 8, wherein the stepped portion is formed on atip of the cannula.
 10. A method according to claim 9, wherein thecannula tip is substantially rigid.
 11. A method according to claim 8,wherein locking the inner cannula relative to the outer cannula includesrotating the inner cannula relative to outer cannula from an unlockedposition to a locked position.
 12. A method according to claim 8,wherein locking the inner cannula relative to the outer cannula includesrotating a hub of the inner cannula relative to a head of the outercannula from an unlocked position to a locked position in which at leastone protrusion of the inner cannula hub is engaged with at least oneridge of the outer cannula head.
 13. A method according to claim 8,wherein the outer cannula includes a tapered portion extending having afirst end with a first outer diameter and a second end with a secondouter diameter larger than the first outer diameter, and a cylindricalportion having a third outer diameter, wherein the stepped portion isdefined by a difference between the second outer diameter and the thirdouter diameter.
 14. A method according to claim 13, wherein the taperedportion and the cylindrical portion of the outer cannula have a constantinner diameter.
 15. A method for manufacturing a medical cannulaassembly, the method comprising: forming an outer cannula, including:forming a first cannula portion having a first outer diameter; forming asecond cannula portion having a second outer diameter larger than thefirst outer diameter of the first cannula portion; and coupling at leastone end of an inflatable cuff to the first cannula portion; wherein thedifference between the second outer diameter of the second cannulaportion and the first outer diameter of the first cannula portion formsa stepped portion configured to reduce an outward bulge of the cuff, andforming an inner cannula configured for insertion into and locking withthe outer cannula.
 16. A method according to claim 15, wherein thesecond cannula portion of the outer cannula tapers from a first endhaving the second outer diameter to a second end having a third outerdiameter smaller than the second outer diameter.
 17. A method accordingto claim 15, wherein: the first and second cannula portions of the outercannula are portions of a cannula tip; and the method further includesattaching the cannula tip to an elongated cannula body.
 18. A methodaccording to claim 15, wherein: the first cannula portion of the outercannula comprises a portion of an elongated cannula body; the secondcannula portion of the outer cannula comprises a portion of a cannulatip; and the method further includes attaching the cannula tip to thecannula body.
 19. A method according to claim 15, wherein the first andsecond cannula portions of the outer cannula are portions of anelongated cannula body distinct from a cannula tip.
 20. A methodaccording to claim 15, wherein the first and second cannula portions ofthe outer cannula are formed integrally.
 21. A method according to claim15, wherein the stepped portion is configured to reduce an outward bulgeof the inflatable cuff, when inflated.